import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
function html2pdf(id, title = document.title) {
  // document.documentElement.scrollTop = 0
  document.body.style.height = 'auto'
  const genPdf = document.querySelector(`#${id}`)
  const padding = genPdf.style.padding
  genPdf.style.padding = '30px'
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      return html2Canvas(genPdf, {
        allowTaint: true
      }).then(function(canvas) {
        const contentWidth = canvas.width
        const contentHeight = canvas.height
        const pageHeight = contentWidth / 592.28 * 841.89
        let leftHeight = contentHeight
        let position = 0
        const imgWidth = 595.28
        const imgHeight = 592.28 / contentWidth * contentHeight
        const pageData = canvas.toDataURL('image/jpeg', 1.0)
        const PDF = new JsPDF('', 'pt', 'a4')
        if (leftHeight < pageHeight) {
          PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
        } else {
          while (leftHeight > 0) {
            PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
            leftHeight -= pageHeight
            position -= 841.89
            if (leftHeight > 0) {
              PDF.addPage()
            }
          }
        }
        PDF.save(title + '.pdf')
        genPdf.style.padding = padding
        resolve('')
      }
      ).catch(() => {
        reject('')
        genPdf.style.padding = padding
      })
    }, 200)
  })
}
export default {
  install(Vue, options) {
    Object.defineProperty(Vue.prototype, '$html2pdf', { value: html2pdf })
  }
}
